Artificial Aging of Crude Oil and Water Remediation by AOPs

Crude oil in the environment is exposed to a series of weather-climatic factors (water, oxygen, solar irradiation) and microorganisms’ action that triggers chemical-physical processes of degradation (known as weathering). In a short time, the original composition of exposed oil can change significantly. In this work, our research team experimented with an Italian crude oil simulating solar irradiation to understand the modifications induced on its composition by artificial aging. Moreover, we studied the transformations deriving from different advanced oxidation processes (AOP) applied as remediation methods on liquid matrices contaminated by petroleum. For the last objective, we adopted different AOPs (photocatalysis, sonolysis, and sonophotocatalysis). as a photocatalyst, we used TiO2 immobilized on a non-woven fabric sheet. Crude oil and its water-soluble fractions were analyzed using GC-MS, 1H-NMR in a liquid state, Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS), and fluorescence. The artificial oil aging induced significant modifications of oil composition with the formation of more oxidized species. All treatments used for the detoxification of polluted water samples, except sonolysis, showed a consistent reduction of organic content with the appearance of potentially toxic substances, confirming that the remediation processes experimented with cannot be applied in natural environments without a careful and repeated experimentation in controlled laboratory conditions.